I quit my job in September of this year to go freelance. I had a long term contract lined up that started mid-October that would net me about $250k+ per year in NYC. At my last job I've contributed about $9k to our Vanguard 401k before leaving.

I setup an EIN At my new contract I'm looking at the optimal savings structure:

Weighing a 401k Solo vs a SEP IRA

Looking to take advantage of a Backdoor conversion.

Considering that it's near the end of the calendar year!

Definitely maximizing my contribution to whatever is possible

For my income level it seemed that a SEP IRA was best, although I have heard there is difficulty conducting a backdoor conversion with this. Admittedly I don't undersrtand why this is the case.

I spoke with an Edward Jones fin advisor that was setting up a plan for me and it looked good but they charge fees over 1% to invest in their own low-cost ETFs (speaking with him later to see if they can move to a flat administrative fee + the ETF administrative fees).

What do you guys think the best savings structure is? Should I factor in my contributions for 2018 401k when making this decision or just focus on the best vehicle for 2019?

And what type of cost should I expect when working with a plan administrator? If there are recommendations for a good flat-fee or low cost plan I would love to hear about it here or through DM.

I quit my job in September of this year to go freelance. I had a long term contract lined up that started mid-October that would net me about $250k+ per year in NYC. At my last job I've contributed about $9k to our Vanguard 401k before leaving.

I setup an EIN At my new contract I'm looking at the optimal savings structure:

Weighing a 401k Solo vs a SEP IRA

Looking to take advantage of a Backdoor conversion.

Considering that it's near the end of the calendar year!

Definitely maximizing my contribution to whatever is possible

For my income level it seemed that a SEP IRA was best, although I have heard there is difficulty conducting a backdoor conversion with this. Admittedly I don't undersrtand why this is the case.

I spoke with an Edward Jones fin advisor that was setting up a plan for me and it looked good but they charge fees over 1% to invest in their own low-cost ETFs (speaking with him later to see if they can move to a flat administrative fee + the ETF administrative fees).

What do you guys think the best savings structure is? Should I factor in my contributions for 2018 401k when making this decision or just focus on the best vehicle for 2019?

And what type of cost should I expect when working with a plan administrator? If there are recommendations for a good flat-fee or low cost plan I would love to hear about it here or through DM.

Do NOT set this up at Edward Jones. Pick a low cost provider like Vanguard or Fidelity.

Since you are self-employed you could consider using a SEP IRA, SIMPLE IRA, or individual (solo) 401k. Vanguard, small-business plans,"Compare plans". That link has a nice table comparing the features (like contribution limits, amount of paperwork required, etc.) of the three types of plans.

At that income level a solo 401k is by far your best option. You can put away your 19k employee contribution, your 20% employer contribution, and still be in the clear for a backdoor Roth IRA. No reason to pay any extra fees at all. Many of us here use fidelity or vanguard, which both have slightly different sets of features that you may or may not care about. Having a plan that takes incoming rollovers (like fidelity but not vanguard), is a way to clear the field of any existing IRAs that might get in the way of a backdoor Roth.

Those links you provided were some interesting reading... any they seem to suggest that if you're interested in a backdoor conversion option that Vanguard is not the way to go and in fact, e-trade seems to be the most promising commercial option! To quote college investor:

Fidelity also offers rollovers into the plan, which can be a great strategy for doing a backdoor Roth IRA.​ However, they don't allow in-service distributions from the plan. Only E*Trade potentially offers this.

I won't lie- I don't know what this means or why it would be important to me but I'm still learning here.

I would do further research on opening an Individual 401(k) at Fidelity, which is what I would do if I were you.

I'll tentatively commit to that and start researching that plan of action. If I want to hire someone to investigate the best type of account and provide information on it, who would I look to hire? I don't think it would be a CPA as I've been getting mixed responses and levels of expertise from them...

One more question: is a Megabackdoor Roth an option that is available to me and, if so, does that change the recommendation?

Not that I have anything against Millennials. Many of them are quite knowledgeable about employer retirement plan options.

Just not the "college investor." There is a lot of information about one-participant 401k plans that are nothing more than personal opinion.

The choice of one-participant 401k providers and trational/Roth IRA custodians has nothing to do with which ease of doing a Backdoor Roth.

At $250K in income especially in NYC, there is no benefit to a Mega Backdoor Roth. For 2019 you will easily be able to make $19K in pre-tax employee elective contributions and $37K employer contributions (which are always pre-tax)

At $250K in income especially in NYC, there is no benefit to a Mega Backdoor Roth. For 2019 you will easily be able to make $19K in pre-tax employee elective contributions and $37K employer contributions (which are always pre-tax)

Ah, so the reason there is no benefit is because my income level allows me to contribute an amount equal to what a lower-income person would be able to contrib with the MBDR strategy?

Living in NYC, I think I would benefit more from being able to make pre-tax contributions (I plan to reitre in a LCOL area)